To Doug Schneider,
I found your answer to my inquiry much as I expected, with a couple of omissions. It seems to me that if it is easy to include a "tone defeat" or "source direct” (as some manufacturers call it) function, which removes any detriment to the sound that tone controls might induce, why not include them in all amps for users who might find them useful? They can always be switched out. The additional cost in a high-end amp would seem to be minimal. I think the main reason for their exclusion is the bias against them by the elitists.
I also feel that with computer modeling and high-tech measuring equipment, it should be easy for any competent designer to devise an analog tone-control circuit that isn't negatively affecting performance. Maybe my ears aren't as good as yours, but on any of the amps I've owned that had a bypass function on the tone controls, I couldn't hear any difference between the bypass setting and with the tone controls activated, but in their flat setting. And in my small room, with rear-ported speakers close to the rear wall, small cuts in bass almost always improve clarity and resolution significantly.
Thanks again for your insight.
For the most part, I agree with you -- some others do too. After I posted my initial response, fellow writer Pete Roth wrote to me to say that he’d been talking about this same issue with speaker designer Richard Vandersteen, who also believes they should be included on preamps to fix up the minor and major problems with various recordings. But they’re not included -- we know that. I’m not sure it’s the elitists who reject them as much as those who are simply uninformed about how such small frequency-response tweaks can change and improve the sound.
The only thing I don’t agree about is the transparency of all controls. On my Nakamich AV-10 receiver, the change in sound is pretty obvious the moment the tone controls are engaged, even when they’re left at their flat settings. Other audiophiles I’ve talked to have said the same thing. Of course, the AV-10, which was a pretty low-priced piece when it was introduced over a decade ago, hardly represents the state of the art in amplification. I’m sure that a great designer with a higher parts budget could create the necessary circuitry and make it totally transparent. . . . Doug Schneider